https://www.city-journal.org/article/can-americans-still-mourn-as-americans
Only a nation can mourn its dead. There is always the abstract reverence for sacrifice, the human awe that acts of valor inspire; that is universal. But to mourn takes something greater. You can admire the Dying Gaul, or Horatius at the bridge; you can only grieve for your countrymen.
This may be, in part, why it took more than a century for Memorial Day to take shape in this country. America was a nation born in war—unlike almost any in history before it—yet the early devotions to its fallen sons were mostly the private remembrances of soldiers’ organizations. A generation of relative peace followed, with fewer than 3,000 battle deaths between 1815 and 1861.
Then came civil war, when secession put the question of the American nation to a mortal test. Recent interpretations left and right have centered slavery at the expense of Union, the principle that Lincoln and other Northern leaders claimed as their motivation: that the American nation was bound by ties of law, of history, of purpose that could not be broken. Ultimately, more than 360,000 Northern men and boys died for that proposition—nearly twenty times as many Americans as had died in all theaters of conflict since 1775.
The war had settled the question: this was one nation. Yet that nation had also been transformed, in no small part because so many thousands of its sons had shed their blood. And so their sacrifice became a central object of the American civil religion: in Lincoln’s famous homage to the fallen men at Gettysburg, in the highly visible practices of the Grand Army of the Republic, and especially in the observance of Decoration Day, when the graves of the war dead would be adorned with flowers, flags, and other objects of patriotic reverence. The remembrance of their sacrifice served doubly to remind the mourners of the cause for which they fought, as a visible illustration of the price by which the Union—the American nation—had been preserved.
This was not the whole story, though. Beside those many Union dead, some 258,000 Americans had fallen in service to the South. Their families and communities would honor them, of course. But what was the nation to do about them?